Puncturing blood vessels is a common practice in medical treatment of human body. Medical personnel have to learn through training and experience to acquire an accurate technique of performing vascular puncturing. However, the blood vessels of patients are not always easily discernible. Especially for elderly patients, the blood vessel becomes calcified, thickened and lost elasticity which makes puncturing the blood vessels more difficult.
Aside from puncturing superficial blood vessels, performing puncture of blood vessel at a deeper location may become particularly challenging. In such a situation, ultrasound image may become very useful and important to guide the direction and depth of the needle to perform a successful and accurate puncturing of a blood vessel without conventional repeated trial-and-error method.
For instance, U.S. Pat. No. 5,924,992 entitled “Semi-compliant needle guide for use with ultrasound transducers” discloses a probe to generate and receive ultrasonic waves that is in contact with a body position where blood vessel puncturing is intended to perform ultrasound detection. Though an external screen connected to the probe ultrasound images can be seen to facilitate blood vessel puncturing operation. However, the operator has to look at the external screen during the blood vessel puncturing operation rather than directly looking at the human body where the puncturing operation is being performed. This design is seriously deficient of human intuition and working ergonomics which are extremely importantly for any procedure tool. The operator has to control the ultrasound needle guide with one hand and control the needle to perform blood vessel puncturing operation with the other hand while the eyes have to look at the external screen. Thus, the design makes the procedure cumbersome and is prone to cause inaccurate puncturing a number of times before making a correct one.
Furthermore, as the blood vessel generally is very small in diameter, a slight deviation could make the needle skewed from the correct puncturing position that could affect the later treatment or surgical operation. Moreover, the aforesaid prior art, referring to its FIGS. 1 and 2, provides a closed type needle locating and guiding bore to facilitate needle positioning and blood vessel puncturing. After the puncturing operation is finished, normally, a guide wire is needed to be inserted into the lumen of the puncturing needle and then advance into the lumen of blood vessel while maintaining the position of the needle tip in the lumen of blood vessel. With the closed type bore being in conjunction with the needle, the ultrasound transducer cannot be removed while performing inserting a guide wire into the blood vessel. This demand of action adds more technical difficulty and increase the chance of failure due to the fact that maintaining a needle tip in the small luminal space of blood vessel is a very delicate move.